Various types of powered door latch systems have been developed. An example of one such arrangement is disclosed in U.S. Pat. No. 9,260,882, entitled “UNIVERSAL GLOBAL LATCH SYSTEM,” issued on Feb. 16, 2016, the entire contents of which are hereby incorporated by reference. Powered door latches may include a powered actuator that shifts the pawl of the latch to thereby shift the latch to an unlatched state. Once the pawl is in the released position, the latch retaining member (or “catch”) can be rotated such that the vehicle door can be opened. Powered latch systems may also include an electrical switch or other unlatch input device at the exterior door handle and/or the interior door handle. In use, a user actuates the switch, thereby generating a signal that is received by a controller. The controller evaluates the signal and generates a signal that causes the powered actuator to shift the pawl to a released position if predefined door unlatch criteria are met, thereby unlatching the powered latch.
Powered latches may utilize a solenoid, electric motor, or other suitable electrically-powered actuator to shift the pawl. The electrically powered actuators are typically powered utilizing the vehicle's main electrical power supply (e.g. a battery). However, electrical energy storage devices such as batteries, capacitors, etc. tend to lose their electrical charge over a period of time. Also, in the event of a malfunction, the vehicle's main electrical power supply may be lost. In the event electrical power is lost, it may not be possible to actuate an electrically-powered latch device.